Sign In | Join Free | My xxjcy.com
China BEST PIPELINE EQUIPMENT CO.,LTD logo
BEST PIPELINE EQUIPMENT CO.,LTD
Your one stop shop for all your piping needs such as Steel Pipes , Forged Flanges, Butt Weld Fittings, Forged Fittings
Verified Supplier

9 Years
Home > Slip on Plate Flange >

347 and 347H Stainless Steel Forged Slip on Plate Flanges with High-Temperature Strength

Product Categories
BEST PIPELINE EQUIPMENT CO.,LTD
Trust Seal
Verified Supplier
Credit Check
Supplier Assessment
Contact Now

347 and 347H Stainless Steel Forged Slip on Plate Flanges with High-Temperature Strength

  • 1
  • 2

Contact Now

347 / 347H Stainless Steel Forged Flanges
347 and 347H are austenitic stainless steels stabilized with niobium (often reported as Nb + Ta). While very similar, 347H is the high-carbon version specifically designed for enhanced high-temperature strength performance.
Chemical Composition
Typical chemical composition ranges for both grades (approximate standard values):
347 Stainless Steel (UNS S34700)
Element Composition (%)
Carbon (C) ≤ 0.08%
Manganese (Mn) ≤ 2.00%
Silicon (Si) ≤ 0.75%
Phosphorus (P) ≤ 0.045%
Sulfur (S) ≤ 0.030%
Chromium (Cr) 17.0 - 19.0%
Nickel (Ni) 9.0 - 13.0%
Columbium + Tantalum (Cb + Ta) 10 × C% min, up to about 1.0% typically
Molybdenum (Mo) Usually not intentionally added (residual typically <0.75%)
Iron (Fe) Balance
347H Stainless Steel (UNS S34709)
Element Composition (%)
Carbon (C) 0.04 - 0.10% (higher than 347)
Manganese (Mn) ≤ 2.00%
Silicon (Si) ≤ 0.75%
Phosphorus (P) ≤ 0.045%
Sulfur (S) ≤ 0.030%
Chromium (Cr) 17.0 - 19.0%
Nickel (Ni) 9.0 - 13.0%
Columbium + Tantalum (Cb + Ta) 8 × C% min, typically up to around 1.0%
Molybdenum (Mo) Generally not a deliberate addition
Iron (Fe) Balance
Key Technical Characteristics
Relation to 304/321 Types
347/347H grades share similar chromium and nickel content with 304/304H, but are stabilized with niobium (instead of titanium like 321) to prevent chromium carbide precipitation and intergranular corrosion in the sensitization range (approximately 450-850°C).
Significance of "H" Grade
The "H" designation (347H) indicates higher carbon content, which provides:
  • Enhanced creep strength
  • Superior high-temperature strength performance
  • Ideal for boilers, heaters, superheaters, and refinery/chemical plant tubing applications
  • Maintained stabilization with niobium to prevent sensitization issues despite higher carbon content
Stabilization Mechanism with Niobium (Nb)
Niobium forms niobium carbides rather than allowing chromium carbides to form at grain boundaries. This mechanism:
  • Preserves chromium in solid solution
  • Maintains corrosion resistance after welding or elevated temperature service
  • Protects against intergranular corrosion
Important Note: For exact composition limits required for design, procurement, or certification purposes, always refer directly to the relevant standards (such as ASTM A240, A182, A213, A312, etc.) and the specific product's mill test certificate (MTC). Different product forms and standards may include slightly different ranges or additional controlled elements.

Product Tags:

347 Stainless Steel Flange

      

347H Stainless Steel Slip on Plate Flange

      

High-Temperature Strength Forged Flange

      
Buy cheap 347 and 347H Stainless Steel Forged Slip on Plate Flanges with High-Temperature Strength product

347 and 347H Stainless Steel Forged Slip on Plate Flanges with High-Temperature Strength Images

Inquiry Cart 0
Send your message to this supplier
 
*From:
*To: BEST PIPELINE EQUIPMENT CO.,LTD
*Subject:
*Message:
Characters Remaining: (0/3000)
 
You May Like